Anti-personnel bomb



Aug. 9, 1966 E. G. REED ANTI-PERSONNEL BOMB 4 Sheets-Sheet 1 Original Filed March 11, 1963 Eowuv G. REED INVENTOR.

ATTOZNEY Aug. 9, 1966 E. G. REED 3,264,985

ANTI-PERSONNEL BOMB Original Filed March 11, 1965 4 Sheets-Sheet Q 7 53 (L9 M (3,7 I 9 46A [9A 19B 46B 5 46 44 4' 40,1: 5

3 45A 468 49 3 46c 54 461: 83 EDWIN 6. R550 INVENTOR.

ATTOQN EV Aug. 9, 1966 E. G. REED ANTI-PERSONNEL BOMB 4 Sheets-Sheet 5 Original Filed March 11, 1963 i mmmmuv EDWIN G. REED INVENTOR.

ATTORN E Y E. G. REED ANTI-PERSONNEL BOMB Aug. 9, 1966 Original Filed March 11, 1965 AXIS OF PRECESSION 4 Sheets-Sheet 4 EDW/N 6 REED INVENTOR.

d laiwww ATTOQNEV United States atent 3,264,985 ANTI-lERSONNEL BOMB Edwin G. Reed, 18937 Nordhotf St., Los Angeles, Calif. Continuation of application Ser. No. 264,208, Mar. 11, 1963. This application July 12, 1965, Ser. No. 471,282 21 Claims. (Cl. 1024) This is a continuation of application Serial No. 264,208, filed March 11, 1963, now abandoned.

This invention relates to an anti-personnel bomb and, more particularly, to an explosive anti-personnel bomb, preferably of the fragmentation type, capable of being launched in a cluster from an aircraft and, upon release from the cluster, adapted to descend with a generally phugoid oscillation, in an expanded, random pattern, and to strike the terrain at a small impact angle at a low vertical impact velocity for greater effectiveness .against enemy ground personnel.

Although the particular as Well as the general terms used herein are well known to those persons skilled in the various arts to which they pertain, the present invention has features which necessitate the use of terms that are not common to all of the arts employed such as, for example, ordnance and aeronautics. Accordingly, for purposes of definition and clarity of description, it should be understood that the term bomb as used herein refers solely to a heavier-than-air device which is dropped from an aircraft, and does not refer to missiles or projectiles whose flight, trajectory or descent paths are controlled or influenced by target-directed forces of selfpropulsion. The term relative wind refers to the resultant force of the surrounding air directed against the bomb due to the movement of the bomb through the air. The term cluster refers to a group or plurality of bombs while they are maintained in a relatively fixed relationship to each other as in a unitary package or configuration, and the term cluster casing refers to the means for maintaining the cluster in such configuration. The term fuse refers to a tube or cord filled or impregnated with, or otherwise constituting, combustible matter for igniting a primer or an explosive charge after a predetermined delay or interval, and is to be distinguished from a fuse, the latter being a mechanical or electrical detonating device. The term primer refers to a cap, tube, or wafer device containing powder or a compound for igniting a fuse, charge, or another device such as a string igniter, and may be actuated by heat, flame or electricity. The term string igniter refers to a generally flexible string or cord device provided with powder or other combustible compound or mixture which burns and provides relatively intense heat and/or flame along the length thereof for igniting other devices or materials, the latter being either adjacent, coupled or tied to the string igniter at any point or region along the length of the string igniter. The term propellant is used to refer to the gas, vapor, and/or products of combustion which cause the propelling forces used to generate rotary or other motions, and the term propellant material is used to refer to a material which generates or releases the propellant; the foregoing latter terms often are used interchangeably herein. The term airfoil refers to a body designed to provide lift as .a result of the relative wind, the term lift referring to the component of the total aerodynamic forces acting on the airfoil that is perpendicular to the relative wind and, due to the nature of the bomb as hereinafter described, is directed substantially radially outwardly from the bomb.

In the preferred form of this invention, a plurality nf explosive anti-personnel bombs are packaged in clusters contained in discrete cluster casings, each casing being designed to be electrically or otherwise initiated ice upon leaving the aircraft and to fall a predetermined distance from the aircraft before expelling its plurality of bombs for later detonation on the ground.

Each bomb is provided with a plurality of circumferentially spaced, elfectively tangential airfoils so that the airfoils are exposed to the relative wind upon expulsion or separation from the cluster casing and the cluster.

Each bomb is provided with means for causing the bomb to rapidly rotate -or spin about its longitudinal axis in the desired rotational direction corresponding to the orientation of the airfoils. The lift created by the airfoils of each bomb is the resultant of and proportional to the product of the airfoil spin velocity and of the bombs linear velocity through the air, i.e., the relative wind. Due to such lift, the bomb deviates from its normal gravitational descent path and achieves a horizontal component of travel which causes flight until the relative wind decreases sufficiently to prevent further flight. The immediately subsequent gravitational descent again increases the relative wind until flight characteristics return. Thus, the bomb descends in alternating flight and descent paths in a manner known as phugoid oscillation, all of'the bombs descending by phugoid oscillations in .a relatively random manner for achieving an expanded random pattern by the time they reach the ground.

The bombs shape is inherently unstable and, therefore, it tends to tumble during the effectively linear portion of its air travel; however, the bombs spinning force causes the tumbling force to precess each of the bombs until the airfoils face the direction of the air tnavel, i.e., face into the relative Wind. Assuming the normal condition of bomb release from the cluster While the cluster descent path still contains a forward velocity component imparted by the aircraft, at the time of release of the bombs from the cluster, each of the bombs has the same initial forward velocity component so that the slight initial dispersal of the released bombs occurs in an approximately vertical plane relative to each other but moving forward in accordance with the forward speed of the cluster at the time of bomb release. Due to the high wind resistance of the bombs occasioned by their aerodynamically resistive configuration during random tumbling descent, their forward velocity is markedly and rapidly decreased or even terminated and, accordingly, their direction of travel becomes primarily downward due to gravity; however, even such wind resistance during initial travel is random in nature due to the random tumbling action of the bombs relative to each other so that each bomb commences its deviation from the other bombs in an approximately horizontal plane. During the travel of the bomb subsequent to release from the cluster, each of the bombs is spinning about its own longitudinal axis, and the longitudinal axes of the bombs are completely nandomly oriented relative to each other immediately upon release from the cluster due to the initial random tumbling action. The effectively gyroscopic action of the bomb spin causes the bomb to process about an axis of precession normal to the spin or longitudinal axis. Due to the presence of relative wind occasioned primarily by gravitational descent, each bomb precesses until its axis of precession is normal to the relative wind and derives a torque axis in directional alignment with the relative wind while rotating about its torque axis until the longitudinal or spin axis is horizontal, whereby the airfoils are oriented relative to the wind in a manner such that aerodynamic lift occurs, initially in a horizontal direction, and the bomb commences a parabolic deviation from its downward descent, i.e., begins to pull out of its dive, and attains an increasingly horizontal component of flight velocity and a gradually decreasing component of vertical descent velocity so that it flies away from its gravitational descent path, in a manner similar to that of a falling leaf. Since each of the bombs is randomly oriented relative to the other bombs in their tumbling and spinning actions, each bomb deviates randomly from the other bombs to achieve horizontal dispersion. A combination of random dispersal directions, as well as further turning due to the subsequent disturbance of each bombs longitudinal axis as the bomb loses its flight capability and tumbles during each recurrent gravitational descent period, causes the bombs to spread and descend in a random pattern whereby, upon reaching the ground, the bombs elfectively carpet the terrain.

In a preferred embodiment, a bomb fuse is ignited during the bombs descent. Because of the phugoid oscillation, the bomb never reaches a high vertical velocity. When it strikes the ground, it rolls or bounces preferably until its explosion occurs. In the preferred fragmentation type of bomb, a relatively large explosivecharge-to-weight ratio causes the bomb to scatter discrete fragments at initially hypersonic velocities over a rel-atively wide area upon explosion.

Each individual bomb preferably comprises a cylindrical housing surrounded by the plurality of airfoils which are longitudinally and exteriorly arranged and are exposed to the air current when the bomb is dropped whereupon the airfoils create a lift as the bomb travels through the air. This lift results in the above-described phugoid oscillation so that, instead of dropping in a straight line due to gravity, the bomb oscillates in a fluctuating random pattern and the plurality of bombs dropped are horizontally dispersed during their fall.

The housing of each bomb preferably is a hollow cylindrical member fitted with an external flange ring. A fragmentation cap includes a pair of discs which are designed to fit into the open ends of the cylindrical member and comprise flat strip steel having one surface stamped or otherwise formed into squares so as to break into discrete fragments in response to explosion. A detonator tube, filled with a slow burning powder, is adapted to be initiated by the propellant charge during or immediately subsequent to bomb descent so as to eventually detonate the bomb on the ground.

In the preferred embodiment, the means for spinning the bomb comprises a propellant material which is ignited substantially simultaneously with the bombs expulsion from the cluster, and the resulting propellant gas, as a product of the propellant material combustion, is expelled through tangential jet outlets or nozzles to cause the bomb to spin while it is falling through the air.

This invention further relates to a means for launching the bombs from the aircraft in a cluster and ejection means for separating the bombs from the cluster, as well as ignition means for igniting the propellant material of each discrete bomb which eventually ignites the detonator for subsequently detonating the bomb on the ground. A plurality of bombs is enclosed in a cluster casing to be simultaneously launched from the aircraft and ignition of the bombs initiated after the launching so that each casing is clear of the aircraft before the bombs are ignited and ejected from the cluster. To accomplish the foregoing eflects, ignition means of each cluster casing is initiated when launched from the launching means on the aircraft so as to ignite a fuse having a predetermined delay for causing the casing to separate during the initial fall and eject the discrete bombs; at the same time as cluster separation occurs, the ignition of the propellant material of the discrete bombs is initiated from string igniters operable from the action of the aforesaid delay fuse. By such means, a solid propellant within each bomb is ignited and burns whereby the gases of such combustion are expelled through passages to cause each bomb to spin about its longitudinal or spin axis. During the bombs fall, its unstable shape and its velocity through the air cause its longitudinal axis to tumble. The gyroscopic action occasioned by the aforesaid spinning of the bomb causes the tumbling force to turn the bomb about its precession axis which is perpendicular to the longitudinal axis as well as perpendicular to the axis of the rotation due to the applied relative wind force (or torque axis). The resulting precession causes the bombs longitudinal axis to turn until it is perpendicular to the relative wind. Initially, the relative wind may be due to the aircrafts horizontal component of velocity to the extent the cluster retains such velocity, and the bombs longitudinal axis will lie accordingly in an approximately vertical plane. As the bombs horizontal speed is being reduced by aerodynamic drag, which is largely due to the bombs shape, the vertical speed is increasing due to the gravitational acceleration. The bombs longitudinal axis then will lie in approximately horizontal plane. Because of the random nature of the bombs expulsion from the cluster and because of the precession of the bombs in the air during intermittent free fall, the bombs will disperse primarily horizontally in a random pattern.

The lift created by the bombs airfoils is proportional to the product of the air-foils spin velocity and the bombs velocity through the air. A lift acts in a direction perpendicular to the air flow, i.e., the relative wind. Initially, the lift will cause the bombs to disperse in an approximately vertical plane. When the bombs air travel becomes due primarily to gravitation, lift forces will cause each bomb to travel with a horizontal component of travel but in randomly different horizontal directions whereby the plurality of bombs will disperse horizontally. Whenever the vertical air velocity becomes appreciable, the lift will increase and the bomb will begin to fly horizontally, thereby reducing the vertical velocity. When the horizontal velocity has been effectively reduced as by aerodynamic drag, the bomb will again fall until the vertical velocity is restored to sufficient magnitude to create lift again for renewed commencement of the horizontal flight pattern. Thus, each of the bombs falls in a phugoid oscillation descent path to achieve a random pattern of horizontal dispersion. In addition, because of this oscillation, the bombs never reach a large vertical velocity and do not strike the ground at large angles or high speeds.

It is therefore an object of this invention to provide a new and improved bomb provided with peripheral air foils for achieving phugoid oscillations whereby a plurality of such bombs descend in a random pattern of dispersion.

Another object of this invention is to provide a new and improved bomb having an internal propellant arranged to discharge from the bomb during its fall to cause the bomb to rotate, thus producing lift.

A further object of this invention is to provide a new and improved .bomb that uses gyroscopic precession to turn the airfoils into the airstream of the relative wind for producing lift.

Another object of this invention is to provide a new and improved bomb that descends with a relatively low upper limit on its vertical velocity.

Yet another object of this invention is to provide a new and improved bomb that strikes the ground at a relatively low incidence angle, and that falls through any foliage within its path before exploding.

Yet another object of this invention is to provide a new and improved bomb with a relatively simple delay fuse which is ignited within a cluster casing after leaving its aircraft delivery and launching system.

Yet another object of this invention is to provide a new and improved cluster casing for containing a bomb cluster during transportation and after launch dropping by an aircraft and which attains separation of the individual bombs during free fall.

Yet another object of this invention is a new and improved means for electrically initiating cluster separation means in the cluster casing subsequent to launching thereof from the aircraft and a new and improved ignition harness for igniting the bombs and expelling them from a cluster casing subsequent to launching thereof from the aircraft.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention both as to its organization and manner of operatlon, together with further objects and advantages thereof, may best be understood by reference to the following descnptron, taken in connection with the accompanying drawings, in which:

FIGURE 1 is .a perspective view illustrating a plurality of bomb clusters sequentially launched from a helicopter and diagrammatically indicating the random descent paths of a few of the bombs released from one of the clusters, in accordance with the present invention;

FIGURE 2 is an end elevational view of a bomb 1ndicating its direction of rotation and its manner of phugoid oscillation as it descends, an example of a descent path being indicated in dash lines in elevation;

FIGURE 3 is a diagrammatic top plan view illustrating an example of the random descent paths for horizontal dispersion of a plurality of bombs upon release from a cluster;

FIGURE 4 is a perspective view of a launching means in accordance with the present invention and illustrated as containing .a plurality of bomb clusters in launching position, one of the bomb clusters being shown in phantom lines in its position upon the delay fuse timing actuation means of the launch means;

FIGURE 5 is a side elevational view, partly broken away and partly in vertical longitudinal section, showing one of the completely assembled bomb clusters, as seen substantially along line 55 in FIGURE 4 in contact with the timing actuation means of the launch means;

FIGURE 6 is a fragmentary transversely sectioned view, partly in elevation of the delay fuse actuation means of the launch means in contact with the bomb cluster casing, as seen along line 6-6 in FIGURE 5;

FIGURE 7 is an elevational end view, partly broken away and partly in section, as seen substantially along line 77 in FIGURE 5, with schematic illustration of the electrical wires and their contacts used for selective ignition of the timed delay fuse;

FIGURE 8 is an exploded perspective view of the cluster assembly of FIGURE 5 prior to assembly of the bombs, string igniters and fuses therewith;

FIGURE 9 is a perspective view of an individual bomb in accordance with the present invention;

FIGURE 10 is an end elevational view of the bomb shown in FIGURE 9, partly broken away'and vertically sectioned, and showing the bomb within its cluster tube with the string igniters in position in the manner illustrated in FIGURE 11;

FIGURE 11 is a vertically longitudinally sectioned view, partly in elevation, taken substantially along line 11-11 in FIGURE 10, showing the details of construction of a bomb and a cluster tube assembly;

FIGURE 12 is a transverse sectional view of one end assembly of a bomb and a cluster tube, as seen substantially along line 1212 in FIGURE 11;

FIGURE 13 is an exploded perspective view of the fragmentation end caps and explosive container portions of the bomb; and

FIGURE 14 is an enlarged fragmentary perspective view of a fragmentation end cap of the bomb portion shown in FIGURE 13.

Referring in detail to the drawings, there is shown by way of illustration, but not of limitation, a new and improved bomb designed and constructed in accordance with this invention and referred to generally by the numeral 10, cluster means 11 for packing the bomb-s so as to be simultaneously launchable in clusters from an aircraft 12 or other carrier, and launch means 13 for launching the clusters from the aircraft.

As previously mentioned, the bombs 10 are adapted to be packaged within the cluster casing 11 which in turn is adapted to be carried within the launch means 13 for sequential discharge or launch of a plurality of clusters 11 from the aircraft 12, as seen in FIGURES 1 and 4.

Referring to FIGURES 1-3 generally, .a plurality of clusters 11 of bombs 10 have been sequentially discharged via the launch means 13 from a helicopter type of aircraft 12 over a general jungle-type terrain target area 14 and, after a selectively predetermined time of free fall descent, a cluster of bombs 10 (indicated by dots in FIGURES 1 and 3) is released from its cluster casing for travel toward the terrain 14 via phugoid oscillatory descent paths, indicated generally by the lines 15. Although a helicopter has been shown for use against relatively concentrated or localized groups of enemy personnel, it is contemplated that a large military cargo-type aircraft carrying in the order of 10,000 bombs can deliver all such bombs in a single bombing run and effectively carpet a terrain area of approximately one-half mile wide and two miles long with effectively uniform distribution of the bombs 10 by virtue of their large numbers and random dispersals.

As a general description, an electrical charge is applied to the cluster casing 11 when it is discharged from the launch rack 13 to initiate means whereby the cluster casing 11 is spread apart after a period of free fall to cause the discrete bombs 10 to be ejected therefrom. Just prior to ejection, a propellant material 16 in each bomb is ignited for causing a propellant 17 to be ejected in jets through nozzle passages 18 during the bombs subsequent travel. The propellant ejection through the peripheral tangential nozzles 18 causes the bomb 10 to spin while it falls and precess into the relative wind. The resulting lift created by the bombs airfoils 19 results in the aforemention phugoid oscillation so that the bomb 10 flies in an expanded pattern as shown in FIGURES 1-3.

Referring to FIGURES 9, 10, ll, 13 and 14 specifically, each bomb 10 comprises a hollow cylindrical housing 20, closed at one end 21 and having an end closure 22 at the other end, with an annular flanged ring 23 intermediate its ends. The housing 20 is made preferably of a frangible material, such as melamine formaldehyde, and may be cast, compression molded, injection molded or otherwise formed. A cylindrical lining 24 is fitted snugly Within the housing 20 and is provided with a pair of frangible end caps 25 and 26 preferably made relatively flat of material such as, for example, steel or the like with their respective inner surfaces 27 and 28 stamped or otherwise formed into connected, relatively small areas such as squares 29 and the like so that a minimum amount of energy is required to break the steel into discrete fragments, each having the shape of such small square area 29. The cylindrical lining 24 may be made of steel or other material. The fragment areas 29 preferably are separated by V-shaped grooves 30 of suflicient depth to permit ready breaking of the caps 25 and 26 along such grooves 30 by the explosive hypersonic shock waves whereby the fragments are driven out both ends in substantially conical patterns for maximum range and anti-personnel impact and piercing effectiveness.

A hollow brass tube 31 extends radially and substantially centrally into the housing 20 through holes 32 and 33 in the housing 20 and lining 24, respectively, and has an inner annular flange 34 formed as by crimping and an end flange 35, with a detonator primer 36 held within the tube 31 between the flanges 34 and 35 for communicating with an explosive charge 37 which fills the chamber defined by the lining 24 and the end caps 25 and 26. The remainder of the tube 31 is filled with a combustible powder 38 to constitute a fuse which is ignited in a manner to be described later.

The airfoils 19 are mounted on an annular collar 39 and are preferably integrally formed therewith and composed of a plastic material. The collar 39 is provided with an offset annular groove 40 whereby the collar 39 may be slid upon the housing 20 with the groove 40 receiving the housing flange 23 in mating engagement.

The collar 39 is secured to the housing 20 as by press-fit engagement or adhesive cement.

The collar 39 has an annular chamber 41, formed by a radially inwardly open slot, and the plurality of angular jet nozzles 18 (four herein shown) communicate between the exterior of the collar 39 and the chamber 41 tangentially therewith. A corresponding plurality of radial recesses 42 are formed in the collar 39 adjacent the outlet of each nozzle 18 and each recess provides an arcuate shoulder 43 adjacent a nozzle 18-. The annular chamber 41 is filled with the ignitable plasticized solid propellant material 16 which communicates with the bomb fuse 38 at the housing hole 32 so that, upon substantially total exhaustion of the propellant material 16 in the manner described herein, the bomb fuse 38 becomes ignited by the propellant. When the bomb fuse 38 burns to the detonator primer 36, the latter is heat actuated for detonating the explosive charge 37.

Before proceeding with a further description of the operation of the bomb 10 itself, together with additional details of construction of the preferred embodiment illustrated, the preferred means and methods employed in the bomb and cluster delivery system in accordance with the present invention will be described.

Referring to FIGURES 5, 7, 8, and 10-12 in particular, a plurality of the bombs 10 constituting a cluster, as previously described, are adapted to be packaged and contained Within the cluster casing 11. As best seen in FIGURES 5, 7 and 8, a plurality of cylindrical cluster tubes 44 (four shown herein) of equal length and slightly shorter-than the cluster casing 11 are symmetrically arranged within the cluster casing 11 in parallel to each other and the longitudinal axis of the cluster casing 11. A plurality of bombs 10 (five shown herein) are nested together in each cluster tube 44 in end-to-end relationship with the airfoils 19 of each bomb 10 overlapping the airfoils of the adjacent bomb. Thus, as shown in FIG- URE 5, the airfoils 19A on one side of bomb collar 39A may extend to contact the next bomb collar 39B while the airfoils 19B extend back from their bomb collar 39B and between the airfoils 19A to contact the first bomb collar 39A.

In its preferred form, the cluster casing 11 comprises a relatively large tube 45 composed of fiberboard or other frangible material, the cluster tubes 44 being composed of similar material but preferably glazed on their interior surfaces. The cluster tubes 44 are glued and/or riveted to the casing tube 45 to form an integral structure therewith. A plurality (four shown herein) of electrically conductive contact bands 46 (individually referenced as 46A, 46B, 46C, and 46D) preferably thin aluminum, are secured around the exterior of the casing tube 45 in longitudinally spaced relationship. A corresponding plurality of insulated electric wires 47 (similarly referenced as 47A-47D) are each riveted at one end to a corresponding one of the contact bands 46 as at 38 so that each of the wires 47 makes an electrical contact with one of the bands 46 and extends axially through the casing tube 45 to the front end thereof (the left end in FIGURES and 8). Intermediate of the contact bands 46, an inexpensive material such as paper, plastic tape or the like is wound or formed about the casing tube 45 to form raised lands 49 higher than the bands 46 and axially spacing and holding the bands 46 against axial displacement along the exterior of the casing tube 45.

A pair of front and rear bulkheads 50 and 51, preferably composed of wood, are provided to fit within the interior of the ends of the casing tube 45 and abut against the ends of the cluster tubes 44. When assembled, the bulkheads are nailed as at 52 (see FIGURE 5) or otherwise secured to the casing tube 45 to provide secure end closures. The mechanical assembly of the cluster casing 11 is enclosed by a pair of cup-shaped end caps 53 and 54 preferably composed of thin fiberglass and snugly engaging the lands 49. The caps 53 and 54 may be sealed together at their common joint 55 to prevent entry of moisture and accidental dislodgement.

Slipped within each of the cluster tubes 44 and at respective ends thereof, there is provided a pair of identical cup-shaped end spacers 56 and 57 (see FIGURES 5, 11 and 12), each having a circumferential configuration as indicated at 58 for nesting with the airfoils 19 of the end bombs 10, and each having a plurality of circumferentially spaced radial holes 59 therethrough for receiving a like plurality of string igniters 60. The number of holes 59 and string igniters 60 correspond to the number of propellant passages 18 (four shown herein) in the bombs 10, the string igniters 60 being wound between the bombs 10 and snugged against the shoulders 43 so as to be adjacent the propellant passages 18. The rear ends 61 of the string igniters 60 are secured interiorly of the rear end spacer 57, as by the illustrated knots, and the igniter front ends 62 are twisted and/or tied together to form a common pigtail, as shown, which is passed through one of the holes 63 in the front bulkhead 50, there being one such hole 63 for each cluster tube 44. The outwardly directed end cavities of the end spacers 56 and 57 contain respective powder charges 64 and 65, preferably composed of plasticized propellant material, the purposes of which will be described later.

The rim of the front bulkhead 50 is provided with a peripheral groove 66 to receive a string detonator 67 (see FIGURES 5, 7 and 8). The front surface 68 of the bulkhead 50 is routed or otherwise formed to receive a time delay fuse, indicated generally at 69, three end primers 70, 71 and 72, and a string igniter 73 formed for location adjacent the bulkhead holes 63. The end primers 70 and 71 are of the electrically actuated type and are both connected to the fuse 69, the primer 70 being connected to one end thereof and the primer 71 being connected to an intermediate portion thereof at 74 via a spur igniter 75. The other end of the fuse 69 is connected to the end primer 72 of the heat actuated type, the latter being connected to one end of the string igniter 73 for ignition thereof. A spur 76 of the fuse 69 is connected to a heat actuated type of end primer 77 which is connected to the string detonator 67 for actuation thereof substantially simultaneously with the ignition of the string igniter 73 by the end primer 72. As illustrated, the pigtails 62 of the bomb-igniting string igniters 60 are tied or otherwise coupled to the bulkhead string igniter 73 for rapidly sequential ignition thereby.

The two axially intermediate contact bands 46B and 46C are connected to the electric end primer 70 by their respective wires 47B and 47C for actuation of the primer 70; similarly, the axially opposed contact bands 46A and 46D are connected to the short fuse primer 71 by their respective electric Wires 47A and 47D. Thus, electric current flow between contact bands 46B and 46C through the end primer 70 will cause actuation thereof for igniting the entire long fuse 69, whereas current flow between the contact bands 46A and 46D through the short fuse primer 71 will cause ignition of only that short portion of the delay fuse 69 counterclockwise (as viewed in FIGURE 7) from the junction 74 (although clockwise ignition of the fuse 69 from the junction 74 also occurs in such case, clockwise burning is non-functional and immaterial in the illustrated arrangement).

FIGURES 1 and 4 illustrate a relatively simple rack 13 for dispensing the bomb clusters 11 from the aircraft 12. Similar but larger racks can be used to launch a larger number of bomb clusters from the tail or side hatches of a cargo aircraft. As illustrated, the rack 13 may extend transversely from the fuselage of the aircraft 12 or is optionally extensible therefrom. The clusters 11 9. may be loaded into the rack 13 through a hinged section (not shown) at the top or back of the rack or by other suitable means. The rack 13 includes, in the simplified form illustrated, substantially parallel sloped members 78 of angle iron upon and between which the cluster casings 11 are supported and confined for gravitational flow from the rack 13. Retainer means are provided, such as a Y-shaped yoke member 79, for retaining the casings 11 on the sloped members 78 so that, when released, the casings are allowed to roll downwardly toward and out an open end 80 of the rack 13. Release control means, designated generally at 81, may be provided with remote control means (not shown) and hold the yoke member 79 in selectively engaged and disengaged relationship with respect to the transversely aligned casings 11. Actuator means, indicated generally at 82, comprise a plurality of knife-edge means 83 (four shown herein), the upper edges of which are preferably serrated, disposed adjacent the rack opening 80 and located in the direction of gravitational flow of the casings 11 so that the casings are guided upon and over the knife-edge means 83 as they flow from the rack 13. The number of knife-edge means 83 corresponds to the number of Contact bands 46 and are axially aligned relative thereto for individual contact with one each of such bands 46, in the manner illustrated in FIGURE 5. As seen in FIGURE 6, the serrated upper knife-edge 84 of each of the knifeedge means 83 pierces the corresponding one of the casing outer caps 53, 54 during the roll of the cluster casing 11 over the knife-edge means 83 so that the knife-edge 84 contacts the electrical contact band 46. Each of the knife-edge means 83 is electrically conductive and is insulated from the other structure and, as is diagrammatically illustrated for convenience, is connected by a respective one of the electrically conductive wires 85 to an electrical power source 86. The wires 85 of the axially outer pair of knife-edge means 83 are provided with a gang switch 87, and the wires of the axially inner pair of knife-edge means 83 are similarly provided with a gang switch 88 whereby either of such pairs may be selectively energized for supplying the ignition energy to either of the primers 70 or 71 via the corresponding contact bands 46 and cluster wires 47.

Thus, when the retainer means 79 are released by the release control means 81, the lowermost cluster casing 11 of the aligned cluster casings in the rack 13 is released and permitted to pass over the knife-edge means 83, only one pair of which is energized, whereby the corresponding one of the end primers 70 or 71 is actuated to ignite the corresponding long or short portion of the time delay fuse 69 as such cluster casing 11 is launched into the air. If the end primer 70 is actuated, the cluster casing 11 will fall a relatively long distance (proportional to the square of the length of the delay fuse 69) before the bombs 10 are expelled from the cluster casing 11 whereby the aircraft 12 can launch its clusters from a relatively high altitude. Similarly, if the outer pair of knife-edge means 83 are energized for actuating the end primer 71, the cluster casing 11 will fall a relatively short distance before expulsion of the bombs 10 and, accordingly, the aircraft 12 can perform its delivery function from a relatively low altitude.

It should be noted that the contact bands 46 are located in axial symmetry on the cluster casing 11 so that the casings can be loaded in the rack 13 without regard \to forwar or rearwar axial directions.

Continuing the description of operation of the abovedescribed apparatus after launch of a cluster casing 11 from the launch means 13, the time delay fuse 69 continues to burn progressively along its length during free fall of the cluster casing 11 until end primers 72 and 77 are actuated by the heat of the burning fuse 69 whereupon two events occur substantially simultaneously, namely, the string detonator 67 is actuated and the string igniter 73 is ignited. Detonation of the string detonator 67 occurs substantially instantaneously along its entire length circumferentially about the annular groove in the bulkhead 50 so that the resulting explosion disintegrates the peripherally enveloping portions of the members 45, 49 and 53 (as best seen in FIGURES 5 and 7). The preferably extremely rapid combustion of the string igniter 73 causes the substantially simultaneous ignition of all of the pigtails 62 (four shown herein, corresponding to the four cluster tubes 44) of the bomb-igniting string igniters 60. As burning of each set of pigtails 62 progresses rapidly for ignition of its corresponding set of string igniters 60 within forward end spacer 56, the heat or flame of combustion causes ignition of the forward propellant charge 64, the explosion of which within its forwardly-directed end spacer chamber or cavity causes the separation of the cluster casing 11 from the forward bulkhead 50 and the just-previously peripherally separated portion of the end cap 53 caused by the explosion of the string detonator 67, thus leaving the front end of the cluster casing 11 open for subsequent ejection of the bombs 10 therefrom.

As the string igniters 60 burn progressively along their length from the forward end spacer 56 to the reanward end spacer 57, they rapidly sequentially ignite the propellant material 16 in the propellant passages or nozzles 18 so that each of the bombs 10 is fully prepared for ejection from the cluster and commencement of its individual descent. When the string igniters 60 are fully burned, the combustion of their rear ends 61 within the cavity of the rearward end spacer 57 causes ignition of the powder charge 65, the explosion of which within the rearwardly-directed chamber in the end spacer 57 drives the end spacers 56 and 57 and the bombs 10 out of their respective cluster tubes 44 into the air, leaving the cluster tubes 44, the rear bulkhead 51 and the remainder of the cluster casing 11 relatively intact and spatially separated from the bombs 10 so as not to interfere therewith. It should be understood that separation of the bombs 10 and spacers 56 and 57 occurs relative to the casing 11 and its components, and it does not matter whether the bombs and spacers are blown free from the casing or vice versa, the stationary and ejected elements depending upon their relative weight ratios.

Although the manner of descent of the bombs 10, both individually and randomly relative to each other so as to achieve random dispersal subsequent to ejection from the cluster casing 11, now should be clear from the foregoing description, the manner of operation and descent of an individual bomb 10 now will be described even more specifically, primarily in connection with FIGURES 1-3, 9 and 10. The propellant material 16 having been ignited at each of the nozzles 18 prior to ejection of the bombs from the cluster casing, the propellant material 16 burns through the passages 18 to that portion of the propellant material contained within the annular chamber 41. The resulting gas is expelled as a propellant 17 from the tangential nozzles 18 for causing the bomb 10 to spin about its longitudinal or spin axis in the rotational direction as indicated in FIGURE 9, i.e., so that the airfoils 19 are headed into the rotational -wind.

During the bombs fall, its unstable shape and its velocity through the air tend to cause its spin axis to tumble. However, the spinning of the bomb about such axis causes a gyroscopi-c action whereby the tumbling force turns the bomb about a precession axis, as indicated in FIGURE 9, which is perpendicular to the spin axis as well as to the indicated torque axis (the axis of rotation of the bomb due to the applied wind force, i.e., the relative wind). The resulting precession causes the bombs spin axis to turn until it is perpendicular to the relative wind; since the relative wind is effectively opposite to the direction of travel of the bomb, it thus becomes clear that the bomb travels with its longitudinal or spin axis oriented transversely to the direction of travel of the bomb, as distinguished from the prior art of bombs,

projectiles and missiles wherein rotation, if any, occurs about an axis in substantial alignment with the direction of travel.

Initially, assuming that cluster separation has occurred while the cluster still retained a substantial component of horizontal velocity imparted by the aircraft delivery, the relative wind will have a substantial horizontal component of velocity and, accordingly, to that extent, the bombs longitudinal axis will lie in an approximately vertical plane. As the bombs horizontal velocity is reduced by aerodynamic drag (which is relatively large due to the bombs external configuration), the vertical velocity increases due to gravitational acceleration. The forces of procession being constantly available so as to constantly maintain the bombs longitudinal axis in a transverse orientation relative to the relative wind, the bombs longitudinal axis will gradually assume an orientation so as to lie in an approximately horizontal plane.

As mentioned before, the lift created by the bombs airfoils 19 is proportional to the product of two velocities, namely, the airfoil spin velocity and the relative wind, the latter being numerically equivalent to the bombs velocity through the air (not necessarily equivalent to the bombs velocity relative to the ground). The lift acts in a direction perpendicular to the relative wind. Initially, such lift will cause the bombs to disperse relative to each other in an approximately vertical plane to the extent that a horizontal component of velocity remains due to aircraft delivery as aforesaid, and dispersion will occur in a random pattern due to the random nature of the bombs expulsion from the cluster and the constant precession of the bombs in the air. When the bombs air travel is due primarily to gravity, the lift forces will cause the bombs to disperse in an approximately horizontal plane.

With the occurrence of appreciable vertical relative wind, occasioned by gravitational descent, the lift will increase and the bomb will begin to fly horizontally thereby reducing the vertical velocity. When the vertical velocity thus has been sufliciently reduced, and the horizontal velocity has been reduced by aerodynamic drag, the bomb again will fall until sufiicient vertical velocity is attained whereby the vertical relative wind again will cause a horizontal flight component to occur. Thus, each bomb falls in a phugoid oscillation descent path, each descent path being completely randomly oriented relative to the descent path of each of the other bombs, so that a random dispersion pattern occurs.

It is important to note that, in addition to obtaining the foregoing objective of random dispersal of the bombs so as to effectively carpet the terrain over a wide area by dropping clusters from a single aircraft, two addition-a1 significant objectives are attained, namely, the prevention of high impact velocities and the assurance of low angles of incidence upon impact. Such effects are highly desirable, particularly in jungle warfare, for two reasons, namely, the prevention of high impact velocity prevents the accidental explosion of the bombs above the ground by contact with the foliage, limbs or trunks of trees, or immediately upon contact with the ground, or burying of themselves in soft ground, and the low incidence angles permit the bombs to roll and/or bounce along the ground for movement past personnelshielding obstructions and into foxholes; still further, the low incidence angles and the spinning of the bombs permit the bombs to work their way through foliage of jungle trees so that their eventual explosions will occur on or near the ground.

It should be clear that, during exhaustion of the propellant material 16, the bomb fuse 38 is ignited by the final portion of the propellant material 16 for actuation of the detonator primer 36 whereupon the explosive charge 37 is detonated for breaking the end caps 25 and 26 into their discrete fragments 29 and exploding them in substantially conical opposite directions for maximum anti-personnel effectiveness. It may be noted that other anti-personnel effects may be achieved, as desired, by appropriate content modifications without deviation from the principles of the present invention.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim .in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

(I claim:

1. An explosive bomb comprising:

a cylindrical housing adapted to contain a quantity of explosive material;

an annular chamber means surrounding said housing and adapted to contain a quantity of combustible propellant material, said chamber means including a plurality of annularly arranged nozzle means communicating between said propellant material and the atmosphere and being directed tangentially relative to said housing whereby the combustion products of said propellant material cause said housing to rotate about its longitudinal axis;

detonator means in said housing communicating with said explosive material;

fuse means in said housing communicating between said propellant material and said detonator means and adapted to be ignited by said propellant material whereupon said detonator means is caused to detonate said explosive material within said housing; and

an array of airfoils secured to said chamber means in circumferentially spaced, tangential relationship to the exterior of said housing in parallel relationship to the longitudinal axis of said housing so as to cause said housing to travel in an unstable pattern when launched from an aircraft, or the like, and so as to prevent acceleration of the fall of said housing.

2. A bomb as defined in claim 1 wherein said airfoils longitudinally extend beyond said bomb housing.

3. A frangible explosive bomb, comprising:

a cylindrical housing of frangible material having ends and an outwardly-extending collar means intermediate said ends, said housing being adapted to house a quantity of explosive material;

means defining an annular cavity in said collar surrounding said housing, said annular cavity being adapted to contain an ignitable propellant material;

means defining a plurality of transverse exhaust passageways in said collar and communicating between said annular cavity and the eaxterior of said collar of said cylindrical housing;

detonator means in said housing and adjacent to said explosive material;

fuse means in said housing communicating between said detonator means and said propellant material and adapted to be ignited in 'response to ignition of said propellant material so as to actuate said detonator means, whereupon said detonator means is caused to detonate said explosive material; and

an array of airfoils mounted on said collar means in spaced, tangential relationship to the exterior of said housing and in spaced parallel relationship to the longitudinal axis of said housing so as to cause said housing to travel in an unstable pattern when launched from an aircraft, or the like, subsequent to the ignition of said propellant means, so as to prevent acceleration of said housing when falling.

4. An explosive device as defined in claim 3,

wherein said exhaust passages are annularly arranged in tangential relationship to said housing so as to rotate said housing during combustion of said propellant material.

5. An explosive device, as defined in claim 3,

wherein said airfoils are positioned so as to cause a gyroscopic precession of said airfoils to rotate said housing in the airstream during its descent.

6. An explosive device, as defined in claim 3,

wherein said airfoils are postured so that said housing descends with a relatively low limit to its vertical velocity.

7. An explosive device, as defined in claim 3,

wherein said bomb housing descends to strike the ground at a relatively low incidence angle thereto.

8. An explosive device, as defined in claim 3,

including a liner of metallic frangible material in said housing and enclosing said explosive material so as to be expelled from said housing in a plurality of discrete fragments in response to detonation of said explosive material.

9. An explosive device as defined in claim 3, comprising:

casing means adapted to hold a plurality of said bombs;

launching means for selectively launching said casing means from said aircraft to be ejected into the airstream of said aircraft;

means initiated by said launching means for separating said casing means so as to ipermit separation of said discrete bombs to drop into said airstream of said aircraft; and

means in said casing means for igniting said propellant material of each of said bombs prior to separation, thereof from said casing so as to initiate phugoid oscillation of the discrete bombs and subsequent and delayed explosion upon said detonation of said explosive material contained therein.

10. An explosive device, as defined in claim 9,

wherein said plurality of bombs are axially nested in said casing means prior to separation of said casing means to expel said bombs.

11. An explosive device, as defined in claim 9,

wherein said launching means includes means for gravitiationally ejecting said casing means.

12. An exlosive device, as defined in claim 9,

wherein said means initiated by said launching means for separating said casing means includes means for initiating separation of said casing into discrete preselected portions of said casing so as to launch selected of said bomb means prior to the others.

13. A bomb having a generally phugoid oscillation descent path, comprising:

a bomb housing provided with chamber means;

a combustible propellant material disposed within said chamber means;

a plurality of jet outlets in said chamber means communicating between said propellant material and the atmosphere whereby the expulsion of the combustion products of such mate-rial through said jet :outlets causes rotation of the bomb about an axis; and

a plurality of airfoils mounted on said housing parallel to such axis, each of said airfoils being disposed with its angle of attack relative to the direction of such rotation of the bomb, said airfoils being at least longitudinally coextensive with said bomb housing in the direction of such axis.

14. A bomb as defined in claim 13 wherein said airfoils longitudinally extend beyond said bomb housing.

15. A bomb having a generally phugoid oscillation descent path, comprising:

a bomb housing having a cylindrical outer surface symmetrical about the bombs center and a longitudinal axis the-rethrough, said housing being provided with chamber means;

a combustible propellant material disposed within said chamber means;

a plurality of jet outlets in said chamber means communicating between said propellant material and the atmosphere, said jet outlets being symmetrically arranged about such longitudinal axis and such center of mass, each of said jet outlets being directed eccentric-ally relative to such longitudinal axis whereby the expulsion of the combustion products of such material through said jet outlets causes rotation of the bomb about its longitudinal axis; and

a plurality of airfoils mounted on said chamber means parallel to such longitudinal axis and longitudinally symmetrical about the bombs center, all of said airfoils being disposed with a uniform angle of attack relative to the direction of such rotation of the bomb.

16. A bomb as defined in claim 15 wherein said airfoils longitudinally extend beyond said bomb housing.

17. A bomb having a generally phugoid oscillation descent path, comprising:

a bomb housing having a cylindrical outer surface symmetrical about the bomb center and a longitudinal axis therethrough;

an annular chamber means surrounding said housing and disposed in a plane passing through such center and at right angles to such longitudinal axis;

a combustible propellant material disposed within said chamber means;

a plurality of circumferentially spaced jet outlets in said chamber means communicating between said propellant material and the atmosphere, said jet out lets being symmetrically arranged about such longitudinal axis, each of said jet outlets being directed eccentrically relative to such longitudinal axis whereby the expulsion of the combustion products of such material through said jet outlets causes rota- -tion of the bomb about its longitudinal axis; and

a plurality :of airfoils mounted on said annular chamber means parallel to such longitudinal axis and symmetrical about the bombs center, all of said airfoils being disposed with a uniform angle of attack relative to the direction of such rotation of the bomb.

18. A bomb as defined in claim 17 wherein said airfoil-s longitudinally extend beyond said bomb housing.

19. A bomb as defined in claim 17 comprising:

casing means adapted to hold a plurality of said bombs as a cluster in an aircraft;

launching means for selectively launching said casing means from said aircraft for ejection into the airstream :of said aircraft;

means initiated by said launching means for separating said casing means so as to permit separation of such discrete bombs from said cluster after such ejection; and

means in said casing means for igniting said propellant material of each of said bombs prior to separation thereof from said casing means.

20. A bomb as defined in claim 19 wherein said airfoils longitudinally extend beyond their respective said bomb housing, and said plurality of bombs are axially nested in said casing means in such cluster.

21. In a bomb adapted for release from a cluster assembly of a plurality of such bombs after initial free fall from an aircraft, the improvement comprising:

a bomb housing having a cylindrical outer surfacesymmetrical about the bomb center and a longitudinal axis therethrough;

an annular chamber means surrounding said housing and disposed in a plane passing through such center and at right angles to such longitudinal axis;

a combustible propellant material disposed within said chamber means and adapted for ignition;

a plurality of circumferentially spaced jet outlets in said chamber means communicating between said propellant material and the atmosphere, said jet outlets being symmetrically arranged about such longitudinal axis, each of said jet outlets being directed tangentially relative to said bomb housing whereby the expulsion of the combustion products of such propellant material through said jet outlets causes rotation of the bomb about its longitudinal axis; and

a plurality of 'airfoils mounted on said annular chamber means and symmetrically extending on either side thereof, all of said airfoils being substantially tangential to said housing and disposed with a uniform angle of attack relative to the direction of such rotation of the bomb.

References Cited by the Examiner UNITED STATES PATENTS 37,940 3/1863 Plant 10249 X 5 1,533,713 4/1925 Tatay 244-9 2,145,508 1/1939 Denoix 10251 3,098,447 7/1963 Hosli 10251 10 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL W. ENGLE, Examiner. 

1. AN EXPLOSIVE BOMB COMPRISING: A CYLINDRICAL HOUSING ADAPTED TO CONTAIN A QUANTITY OF EXPLOSIVE MATERIAL; AN ANNULAR CHAMBER MEANS SURROUNDING SAID HOUSING AND ADAPTED TO CONTAIN A QUANTITY OF COMBUSTIBLE PROPELLANT MATERIAL, SAID CHAMBER MEANS INCLUDING A PLURALITY OF ANNULARLY ARRANGED NOZZLE MEANS COMMUNICATING BETWEEN SAID PROPELLANT MATERIAL AND THE ATMOSPHERE AND BEING DIRECTED TANGENTIALLY RELATIVE TO SAID HOUSING WHEREBY THE COMBUSTION PRODUCTS OF SAID PROPELLANT MATERIAL CAUSE SAID HOUSING TO ROTATE ABOUT ITS LONGITUDINAL AXIS; DETONATOR MEANS IN SAID HOUSING COMMUNICATING WITH SAID EXPLOSIVE MATEIRAL; FUSE MEANS IN SAID HOUSING COMMUNICATING BETWEEN SAID PROPELLANT MATERIAL AND SAID DETONATOR MEANS AND ADAPTED TO BE IGNITED BY SAID PROPELLANT MATERIAL WHEREUPON SAID DETONATOR MEANS IS CAUSED TO DETONATE SAID EXPLOSIVE MATERIAL WITHIN SAID HOUSING; AND AN ARRAY OF AIRFOILS SECURED OT SAID CHAMBER MEANS IN CIRCUMFERENTIALLY SPACED, TANGENTIAL RELATIONSHIP TO THE EXTERIOR OF SAID HOUSING IN PARALLEL RELATIONSHIP TO THE LONGITUDINAL AXIS OF SAID HOUSING SO AS TO CAUSE SAID HOUSING TO TRAVEL IN AN UNSTABLE PATTERN WHEN LAUNCHED FROM AN AIRCRAFT, OR THE LIKE, AND SO AS TO PREVENT ACCELERATION OF THE FALL OF SAID HOUSING. 